Educational interventions for physical activity among Brazilian adults: systematic review

ABSTRACT OBJECTIVE To summarize the main evidence from educational interventions designed to increase levels of physical activity (PA) among Brazilian adults. METHODS Systematic review of intervention studies carried out in Brazil that implemented educational components aimed at promoting increased levels of PA among adult populations (18 to 65 years old). In October 2020, systematic searches were conducted in six databases, and in the reference lists of the assessed studies. RESULTS Of the initial 2,511 studies, nine were included in the synthesis. Samples with specific characteristics (such as social vulnerability, physical inactivity, and overweight or obesity) were observed, with a greater number of women. Five interventions (55.6%) occurred in primary healthcare settings (PHC) of the Brazilian Unified Health System (SUS). Only four studies (44.4%) described the pedagogical frameworks structuring the educational approaches, among which counseling was the most used strategy, such as those carried out through face-to-face meetings, home visits, lectures, and phone calls (n = 8; 88.9%). Positive results were observed in three different indicators: increase in weekly PA volume (n = 4); increase in leisure-time PA rate (n = 1); and increase in the proportion of women classified as “very active/active” (n = 1). Given the sampling specificities, the domain “participant selection” showed a high number of interventions with high risk of bias. CONCLUSIONS Educational approaches engendered some positive effects on different PA indicators, notably counseling as the main strategy used and approaches involving other health themes, such as nutrition and stress. However, considering the several determinants of PA in Brazil, future interventions should be conducted in different locations of Brazil in order to evaluate, in a broader way, their implementation processes and articulation with the many professionals working in PHC.


INTRODUCTION
Due to the multidimensional impacts it has on an individual's life, physical activity (PA) has been identified as an important factor for human development 1 . More specifically, PA is recognized to be a determinant of several positive health indicators 2 , so that actions and policies for its promotion at the population level and throughout the life cycle have been advocated by several health agencies around the world 3,4 .
In the last decades, PA promotion has deserved much attention in the Brazilian public health agenda, especially for its introduction in the Brazilian Health System (in Portuguese: Sistema Único de Saúde -SUS) and in several national public policies 5 . However, despite this favorable institutional scenario, "promoting PA" is not a simple task in Brazil, since factors such as gender, income, education, and environment [6][7][8] are determinants of its practice.
Primary healthcare (PHC) settings are, thus, potential settings for the implementation of strategies 9,10 to reduce inequities in access to PA. In the SUS context is can potentially increase the completeness and resoluteness of healthcare, enhancing the ability to promote PA in contexts of different levels of social vulnerability 11,12 .
Literature also suggests that interventions based on educational processes 13 entail favorable results to increase PA levels at different moments of life. This evidence, however, is mainly supported by data from interventions developed in high-income countries. Even with the existence of a systematic review of interventions in Latin American countries 14 , the relevance of a more specific synthesis of the Brazilian studies is justified, as it would enable a debate grounded in the Brazilian reality, besides pointing out possible advances toward future national surveys.
This study aims at summarizing the main evidence of educational interventions designed to increase the PA levels of Brazilian adults.

METHODS
This study is characterized as a systematic literature review, with methodology and operational process based on "The Cochrane Handbook for Systematic Reviews of Interventions" 15 , and on the items of the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) 16 list, respectively. This review is part of a larger project named "Translation of evidence for decision making in the Brazilian public health system: a review of interventions aiming physical activity promotion", registered in the PROSPERO database (CRD42015015993).
The inclusion criteria were designed based on the "PICOS" logic, considering that the synthesis would be made up of original scientific studies with the following characteristics: (I) Participants: adult populations, without disabilities, health conditions, or specific diseases, except for samples exclusively composed of participants with overweight or obesity; (II) Interventions: developed in Brazil, implemented in community settings (such as territories, PHC centers, outpatient clinics, and community organizations) and based on educational actions aimed to increase PA levels, regardless of the form of contact (face-to-face or remote meetings) and approach (individual or group); (III) Comparators: no restrictions were imposed regarding the activities performed by the control groups (if there were more than one control group, it was decided that the group that had received the least theoretical and/or practical content would be chosen); (IV) Outcome: PA levels, regardless of the PA indicators used (such as levels of moderate or vigorous PA, and number of steps a day), contexts observed (such as total PA, leisure time displacement time), and the instruments used to measure these (such as questionnaires and motion sensors); and (V) Study design: all types of intervention studies ("trials"), with no restrictions regarding the presences of randomization between groups and/or control group. . In addition to this strategy, manual searches were performed in the reference lists of the studies assessed by its full-texts.
The titles, abstracts and full texts assessments were performed independently by six researchers (AM, HF, GC, IC, JF and WW), supported by a senior researcher to clarify doubts, and establish consensus (PG). Data extraction was also conducted by the same six researchers, also independently, and supported by two senior researchers (ER and PG), on a spreadsheet initially divided into three domains: (I) descriptive features (such as intervention name/acronym, location, population description, and age/age group); (II) methods (such as recruitment and implementation location, group size at baseline and sample losses, description and strategies used in the intervention and control groups, intervention implementation team, and instruments and procedures used for measuring PA); and (III) PA-related outcomes (such as variables analyzed, procedures used for PA data analysis, and statistical magnitude and significance of findings based on "p-value"). Regarding the outcomes of interventions, effect sizes were considered for synthesis, as well as the results of the statistical comparison tests.
The risk of bias of the included studies was assessed by two researchers (ER and PG) using an adapted version of the EPHPP 17 instrument, which assesses seven methodological domains of an intervention study: "selection bias", "adjustment of confounding variables", "methods used in data collection", "losses and dropouts", "intervention integrity", "protocol used in the analysis", and "use of intention to treat".

RESULTS
The electronic database searches resulted in 2,511 potentially relevant studies, of which 165 were initially identified as duplicates and thus excluded from the process (Figure 1). At the end of the evaluation by titles and abstracts, 110 studies were selected for reading of their full texts. Considering the exclusion of 102 of these, mainly due to "age group" (n = 36) and "study design" (n = 29), and the inclusion of one study retrieved by manual search on reference lists, the descriptive synthesis of the current review was composed from data of nine intervention studies conducted in Brazil 18-26 .
As for duration, interventions ranged from two 20 to 12 months 21,26 , and five of them (55.6%) were developed over at least six months 18,19,21,22,26 (Table 2). In two interventions, participants were followed up and evaluated for six months after the end of the intervention 19,26 . In regard of settings, we may highlight five interventions taking place in PHC settings of the SUS, either in health units 19,22,24,26 ,    In four studies 22,24-26 (44.4%), it was observed the description of pedagogical frameworks structuring the educational approaches, so that different approaches were combined in two studies 22,26 : the Social Cognitive Theory 25 and Paulo Freire's educational method 24 (Table 2). Regarding the strategies adopted in the educational processes, counseling was used in eight interventions (88.9%), either through face-to-face meetings 18,19,21,23,26 , home visits 22,24 , lectures 24 , or phone calls 20 . Three interventions delivered educational materials [23][24][25] , while three interventions implemented hands-on activities 19,21,26 . In addition, five interventions addressing other health topics in their educational actions, such as nutrition 18,21,23,25,26 and stress 26 were also identified.
With the exception of the study by Meurer et al. (2019) 25 , all the interventions included used questionnaires to assess PA, with higher frequency of use of the IPAQ versions (n = 6) 18,19,[21][22][23]26 .
In addition to the questionnaire, two studies also used accelerometers to measure PA 19,26 . Samples ranged from 14 20 to 291 25 participants (Table 3). According to Figure 2, methodological potentialities were observed in the domains "methods used in data collection" and "analysis protocol", where all studies were classified as having "low" risk of bias. On the other hand, "participant selection" was the domain where a higher frequency of studies assessed as high risk were found, especially due to specificities in four samples (such as overweight/obese people 18 , people living in regions of high vulnerability 19,26 and physically active 21,23,25 or inactive 19,20,26 people), which limit the generalizability of the   High original evidence. The domain "intervention integrity" showed seven studies rated as moderate risk of bias 20-26 , because they did not report the assessment of consistency of the intervention, and did not mention the risk of contamination between the groupsi.e., the influence caused by the possible proximity of people between the groups, so that those assigned to the control group may also be exposed to the actions conducted to the intervention group.

DISCUSSION
Based on data from nine interventions conducted in six Brazilian cities, from three regions of the country, the current synthesis pointed out positive results in three different PA indicators: (I) increase in weekly PA volume 18,23,25,26 ; (II) increase in leisure time PA index 24 ; and (III) increase in the proportion of women ranked as "very active/active" 21 . Despite the great heterogeneity among pedagogical frameworks that supported the educational processes, counseling practice was the strategy most often adopted by the interventions, regardless of their format and the content approached, also highlighting approaches in other health-related topics, such as nutrition and stress.
Given the growth of academic production related to PA and health topic in Brazil 27 , the number of interventions can be considered to be low. However, this scarcity may be justified by the current context of cuts of budget for research in Brazil 28,29 , besides the fact that intervention studies demands longer time to be developed, as well as more funding and larger teams. Most studies did not report the pedagogical frameworks that supported the educational approaches. Considering that some of the strategies were conducted in the context of the PHC-SUS, which is grounded in premises of health promotion, this is an important gap, including for understanding their alignment with the main national policies, the paths of strategies, and the role of players involved throughout the implementation process. The four studies 22,[24][25][26] with available information based their interventions on different frameworks, either grouped or isolated, thus limiting more in-depth comparisons.
In view of the limitations perceived in the information-based approaches, it is suggested that future interventions also incorporate knowledge from Behavioral Economics 31 , particularly regarding its notion that knowledge, although important, is insufficient in most cases since it disregards the action of non-conscious processes that determine our choices 32 .
Furthermore, it is worth mentioning the importance of ecological or socio-ecological approaches and models, which include several factors from different "levels" that influence human behavior, in a perspective that goes beyond the understanding of health as a mere state of absence of disease 33 . Although educational strategies may play an important role in promoting PA levels, one should not lose sight of the fact that these should be implemented in parallel with the approach of many other factors 31 .
Regarding counseling, which was the most used educational strategy among the studies included, there are records on its positive influence on behavioral change stages 34 , as well as its effect on increasing PA levels 35 . A nationwide study indicates that PA counseling is a practice used by most physicians and nurses working in PHC 36 , even though many of them have little technical knowledge on PA-related issues.
As with the issue of pedagogical references, most of the studies included in the synthesis did not report important elements of the counseling processes, such as: concepts and topics approached, sequential logic subjects, as well as actions aimed at the broader concept of "PA promotion", involving elements of identification and overcoming of barriers to the practice, for example. This finding reinforces the results found by Gagliardi et al. (2015) 37 and, since the continuous offer of counseling is associated with maintaining high levels of PA in the long term, it is important to design strategies (such as training courses and guidelines) for the different professionals working in PHC 38 , in order to provide suitable theoretical and practical subsidies for strengthening it as a public health strategy 39 .
On the other hand, it should be emphasized that the practice of counseling -and any other strategy conducted alone -may be not enough to improve PA indicators: these themes need to be more present in people's lives, either through information or other forms of interventions 33 . In other words, beyond the implementation of specific and/or isolated strategies, it is important that the "PA theme" be more present in people's lives, since PA promotion is a cross-sector theme by nature.
In this spectrum, we highlight the importance of consistent planning of the built environment of cities, in order to expand people's access to PA practice rooms. We could mention the opening of bike lanes which, besides physical demarcation of public roads, require traffic laws to ensure cyclists' safety, as well as improvements in safety and lighting on public roads, favoring active transportation at different times of the day.
On the other hand, considering that most of the interventions included were developed in PHC-SUS settings, counseling for PA may be interconnected with the demands of other healthcare professionals, in the sense of more comprehensive guidance focused on healthy lifestyle habits, and the corresponding improvement of health conditions of a given person or group of people 39 . This suggestion is emphasized by this synthesis, since interventions were implemented by different specialists, not only by Physical Education professionals.
It is also worth mentioning the interventions that addressed other health themes, such as nutrition 18,21,23,25,26 and stress 26 . Recognizing the emergence of the use of electronic appliances as an auxiliary tool to healthcare 40 , it can be suggested that future national studies test the introduction of applications with educational content and/or digital counseling under the prism of PHC. It is worth mentioning the promising results of interventions that use digital counseling for reducing systolic blood pressure 41 .
Even if it was not the objective of the study, but a gap perceived during the process of reading and extracting original data, it is recommended that future interventions report more deeply important internal and external elements such as adoption, scope, effectiveness, implementation and maintenance, as recommended by the RE-AIM instrument 42 . It is recognized that processes of consistent implementation, which articulate different health professionals with different levels of experience, allow greater generalization, and greater possibility of using this information in decision-making 42 . A previous systematic review suggests the weakness of reports on the Brazilian school-based interventions in the domains of adoption, implementation, and maintenance 43 .
Recognizing that the effectiveness of an intervention is directly related to how it is implemented, future studies are recommended to evaluate, in a broader perspective, the process of delivering these strategies, not disregarding the specificities of the SUS PHC settings. Thus, some starting points may be listed, such as: (I) prior recognition of the territories and their respective health needs, by approaching residents and community health agents; (II) permanent dialogue with the many PHC actors, in order to acknowledge the different possibilities of action, and encourage the articulated engagement of the multiprofessional team, from the initial proposal negotiations to the evaluation process; and, (III) expanded health approaches beyond the "AF theme", developed in groups and complying with the logic of PHC.
This review has some limitations, such as (I) the little conceptual report of the elements that make up the intervention, (II) the congruence of strategies developed in SUS spaces with national policies on PHC, as well as the use of different (III) intervention designs, (IV) populations and contexts, and (V) PA indicators. Given these heterogeneities, we chose not to conduct the meta-analysis. On the other hand, as a major strength, it may be highlighted the more specific focus on educational strategies, which allowed the identification of important gaps, such as absence of reports on the pedagogical guidelines of the interventions, and on the consonance of protocols with the ideals of health promotion in Brazil.
Finally, the available set of Brazilian interventions suggests that the educational approaches produced some positive effects on different PA indicators, highlighting counseling as the main strategy used, and the approaches that involved other health themes, such as nutrition and stress. However, considering the several determinants of PA in Brazil, it is important that future interventions be conducted in different locations of the country, so as to comprehensively evaluate their processes of implementation and articulation with the different professionals working in PHC.